From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Lorenzo Bianconi <lorenzo@kernel.org>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, davem@davemloft.net,
lorenzo.bianconi@redhat.com, brouer@redhat.com,
echaudro@redhat.com, sameehj@amazon.com, kuba@kernel.org,
john.fastabend@gmail.com, daniel@iogearbox.net, ast@kernel.org,
shayagr@amazon.com
Subject: Re: [PATCH v2 net-next 6/9] bpf: helpers: add bpf_xdp_adjust_mb_header helper
Date: Thu, 3 Sep 2020 18:13:58 -0700 [thread overview]
Message-ID: <20200904011358.kbdxf4awugi3qwjl@ast-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <b7475687bb09aac6ec051596a8ccbb311a54cb8a.1599165031.git.lorenzo@kernel.org>
On Thu, Sep 03, 2020 at 10:58:50PM +0200, Lorenzo Bianconi wrote:
> +BPF_CALL_2(bpf_xdp_adjust_mb_header, struct xdp_buff *, xdp,
> + int, offset)
> +{
> + void *data_hard_end, *data_end;
> + struct skb_shared_info *sinfo;
> + int frag_offset, frag_len;
> + u8 *addr;
> +
> + if (!xdp->mb)
> + return -EOPNOTSUPP;
> +
> + sinfo = xdp_get_shared_info_from_buff(xdp);
> +
> + frag_len = skb_frag_size(&sinfo->frags[0]);
> + if (offset > frag_len)
> + return -EINVAL;
> +
> + frag_offset = skb_frag_off(&sinfo->frags[0]);
> + data_end = xdp->data_end + offset;
> +
> + if (offset < 0 && (-offset > frag_offset ||
> + data_end < xdp->data + ETH_HLEN))
> + return -EINVAL;
> +
> + data_hard_end = xdp_data_hard_end(xdp); /* use xdp->frame_sz */
> + if (data_end > data_hard_end)
> + return -EINVAL;
> +
> + addr = page_address(skb_frag_page(&sinfo->frags[0])) + frag_offset;
> + if (offset > 0) {
> + memcpy(xdp->data_end, addr, offset);
> + } else {
> + memcpy(addr + offset, xdp->data_end + offset, -offset);
> + memset(xdp->data_end + offset, 0, -offset);
> + }
> +
> + skb_frag_size_sub(&sinfo->frags[0], offset);
> + skb_frag_off_add(&sinfo->frags[0], offset);
> + xdp->data_end = data_end;
> +
> + return 0;
> +}
wait a sec. Are you saying that multi buffer XDP actually should be skb based?
If that's what mvneta driver is doing that's fine, but that is not a
reasonable requirement to put on all other drivers.
next prev parent reply other threads:[~2020-09-04 1:14 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 20:58 [PATCH v2 net-next 0/9] mvneta: introduce XDP multi-buffer support Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 1/9] xdp: introduce mb in xdp_buff/xdp_frame Lorenzo Bianconi
2020-09-04 1:07 ` Alexei Starovoitov
2020-09-04 7:19 ` Jesper Dangaard Brouer
2020-09-04 15:15 ` David Ahern
2020-09-04 15:59 ` Jesper Dangaard Brouer
2020-09-04 16:30 ` David Ahern
2020-09-07 18:02 ` Jesper Dangaard Brouer
2020-09-08 1:22 ` David Ahern
2020-09-03 20:58 ` [PATCH v2 net-next 2/9] xdp: initialize xdp_buff mb bit to 0 in all XDP drivers Lorenzo Bianconi
2020-09-04 7:35 ` Jesper Dangaard Brouer
2020-09-04 7:54 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 3/9] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Lorenzo Bianconi
2020-09-06 7:33 ` Shay Agroskin
2020-09-06 9:05 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 4/9] xdp: add multi-buff support to xdp_return_{buff/frame} Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 5/9] net: mvneta: add multi buffer support to XDP_TX Lorenzo Bianconi
2020-09-06 7:20 ` Shay Agroskin
2020-09-06 8:43 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 6/9] bpf: helpers: add bpf_xdp_adjust_mb_header helper Lorenzo Bianconi
2020-09-04 1:09 ` Alexei Starovoitov
2020-09-04 8:07 ` Lorenzo Bianconi
2020-09-04 1:13 ` Alexei Starovoitov [this message]
2020-09-04 7:50 ` Lorenzo Bianconi
2020-09-04 13:52 ` Jesper Dangaard Brouer
2020-09-04 14:27 ` Lorenzo Bianconi
2020-09-04 6:47 ` John Fastabend
2020-09-04 9:45 ` Lorenzo Bianconi
2020-09-04 15:23 ` John Fastabend
2020-09-06 13:36 ` Lorenzo Bianconi
2020-09-08 19:57 ` John Fastabend
2020-09-08 21:31 ` Lorenzo Bianconi
2020-09-09 20:51 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 7/9] bpf: helpers: add multibuffer support Lorenzo Bianconi
2020-09-03 21:24 ` Maciej Fijalkowski
2020-09-04 9:47 ` Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 8/9] samples/bpf: add bpf program that uses xdp mb helpers Lorenzo Bianconi
2020-09-03 20:58 ` [PATCH v2 net-next 9/9] net: mvneta: enable jumbo frames for XDP Lorenzo Bianconi
2020-09-04 1:08 ` [PATCH v2 net-next 0/9] mvneta: introduce XDP multi-buffer support Alexei Starovoitov
2020-09-04 7:40 ` Lorenzo Bianconi
2020-09-04 5:41 ` John Fastabend
2020-09-04 7:39 ` Lorenzo Bianconi
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